resumo
Ionic Liquids (ILs) are generically regarded as environmentally harmless and thus, assumed as non-toxic. However, due to the endless design possibilities, their ecotoxicological profile is still poorly known. An accurate knowledge on the toxicity of a substance is required, under the scope of environmental regulation worldwide, before their application and commercialization. Knowledge on the relationship between the chemical structure and toxic effects is essential for the future design of more biocompatible solvents. Focusing on the use of ILs as base lubricants, lubricant additives, or even as potential working fluids for absorption heat pumps, the knowledge on its environmental impact is of great importance, due to the possibility of spills. In this specific context, four analogues of glycine-betaine-based ILs (AGB-ILs) and four glycine-betaine based ILs (GB-ILs) were synthesized and characterized. Their ecotoxicity was assessed using representatives of two trophic levels in aquatic ecosystems, the bacteria Allivibrio fischeri (commonly used as a screening test organism) and the microalgae Raphidocelis subcapitata (as an alternative test organism that has been proven very sensitive to several IL families). The microalgae were more sensitive than the bacteria, hence, following a precautionary principle, we recommend considering the toxicity towards microalgae as an indicator in future studies regarding the focused ILs. Although four of the studied ILs were derived from a natural amino acid, all were considered hazardous for the aquatic environment, disproving the primary theory that all ILs derived from natural compounds are benign. Furthermore, the modification in the structure of anion and the cation can lead to the increase of toxicity.
palavras-chave
THERMAL-STABILITY; AQUATIC TOXICITY; BIODEGRADABILITY; ECOTOXICITY; PHOSPHONIUM; DESIGN; GROWTH; ANION
categoria
Environmental Sciences & Ecology; Toxicology
autores
Parajo, JJ; Macario, IPE; De Gaetano, Y; Dupont, L; Salgado, J; Pereira, JL; Goncalves, FJM; Mohamadou, A; Ventura, SPM
nossos autores
Sónia Patrícia Marques Ventura
Professor AuxiliarProjectos
CICECO - Aveiro Institute of Materials (UID/CTM/50011/2019)
Projeto de Investigação Exploratória: Sónia Patricia Marques Ventura (IF/00402/2015)
agradecimentos
This work was developed within the scope of the projects EM2013/031 and GRC ED431C 2016/001 (Xunta de Galicia, Spain) and by the network ReGaLIs R2014/015 (Xunta de Galicia, Spain). This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, FCT Ref. UID/CTM/50011/2019, financed by national funds through the FCT/MCTES. Thanks are due for the financial support to CESAM (UID/AMB/50017/2019), to FCT/MCTES through national funds. This work is a contribution to the project PTDC/ATP-EAM/5331/2014, funded by FEDER, through COMPETE2020 - POCI, and by national funds throughY FCT/MCTES. J.L. Pereira is funded by national funds (OE) through FCT, under a framework contract (art. 23, DecreeLaw 57/2016, changed by Law 57/2017); I.P.E. Macario is a recipient of an individual research grant by FCT (SFRH/BD/123850/2016) financed by the FCT/MEC and co-financed by FEDER program. S.P.M. Ventura acknowledges the financial support from FCT by the IF project IF/00402/2015. J.J. Parajo thanks to COST Action CM1206 EXIL.